Expansion reamer



June 26, 1928. 1,674,890

E. E. DAVIS EXPANSION REAMER Filed Oct. 27, 1922 Patented June 26, 1928.

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This invention relates to reamers and more particularly to reamer-s of the expansion type. 7

One of the objects of this invention is to provide an expansion reamer in which the blades are arranged for expansible adjustmentand which shallbe provided with novel means tor rendering .such adjustment per.- -manent. Another object of this invention is .to pro.- -v'ide a reamer in which the sliding blades are equipped with means for locking the bladesefi'cti-vely in adjusted position.

*Further iobjects will appear from. the detail description taken inconnection with the accompanying drawing, =in which:

Figure 1 is a longitudinal view, partly in section, showing a reamer head embodying this invention;

Figure 2 is a section on line 2-2, Figure 1;

Figure 3 is, a partial end view showing the method of locking the blades;

Figure 4 is a section on line 4.4;, Figurev3-;

Figure 5 is -a section on line 5+5, Figure 1 and V Figure 6 is an enlarged detail perspective {illustrating the arrangement of the locking ins. gIn the embodiment-ofthis invention illus- --tr ate din{thedrawing, 1. designates a reamer -head which is usually cylindrical in .shape and-is provided with a bore 2 adapted to receive a shank for :mounting the same in av machine or holder and with clutching means-such as the notch 3, adapted to receive a dogon the shank to provide-a driving connection. The head 1 is provided with a series o-f-bladereceiving slots 4, the bottoms 5 of which are inclined outwardly toward the tip of the head. A series of blades 6 is provided, each of which fits into one of the slots 1 so as to be slidable therealong. The lower edge 7 of each blade is beveled to a degree corresponding to the incline of the bottom 5 of the slot 4. so that when the blade 6 rests with its bottom edge 7 against the bottom 5 of the slot, the outer cutting edge 8 will be practically parallel with the axis of the reamer. By means of this arrangement the blades may be expanded by moving them along the slots 4 toward the tip of the reamer.

The body of the reamer 1 is provided with a suitable thread upon which an adjust,-

The collar 10 is provided with a radial face adapted to engage the radially disposed faces 11015 the heels of the blades 6. The ring 10 bears against the heels of the blades and-provides an abutment for adjusting said blades along the slots 4. By turning the ring 10 on the thread 9 the blades may be moved "forward or toward the tip of thejcutter and along the slots 4; and by such movement the cutters are expanded. A backing ring 12 maybe threaded on the thread .9 and screwed up to engage the adjusting ring 10 so as to secure said adjusting ring in adjusted position. Suitable sockets 153 may be provided for the engagement 05f wrenches for, turning the rings 10 and 12.

, in order to hold the blades in adjusted position in the head, standard taper pins 14; are provided. Each of these pins is adapted to engage a groove 15 in the corresponding blade 6. The arrangement of ,the pins 14: (is shown in detail in Figures 5 and 6. Figure 6 has been drawn to a somewhat enlarged scale and the angles of the pins and slots have been somewhat exaggerated so as to show the construction more clearly. Each .pin 14 is adaptedto fit into ataper .groove 16. This groove is provided by drilling .a taper hole in the head 1 at an angle both with the axis of the reamer {and with the plane ot'the blade'6. This taper groove ,16 is so adjusted that the intersection between its wall and the wall of the slot .4 provides an edge 17 whichis parallel to the bottom 5 ofthe slot 4 and an uppe-redge 18 which makes an angle therewith. The groove {16, however, comprehends the ,major part of .a circle, so that when the pin 14 is .driven therein. it will be held in position while projecting into the slot 4:. Each blade 6 is provided with a straight groove 19. By straight groove is meant one of uniform cross-section throughout its length. This groove is so placed that its lower edge 20 will, when the blade is seated in the slot 4, substantially coincide with the edge 17 of the taper groove. It will be evident from a study of Figure 6 that when the blade 6 is seated in its slot and the pin 14: driven into the groove 16, the pin will bear against the lower edge 20 of the groove 19 in the blade, and the pin will also bear against the upper surface of the taper groove. Since this ing ring vor collar 10 is adapted to turn upper surface is at an angle with the edge 20, a wedging action Will take place tendingxto force the blade-6 downwardly and firmly to seat the same against the bottom 5 of the slot 4. At the same time this Wedging action will have an angular component tending to force the blade 6 against the side of the slot. Since theipin lengages the edge 20 through the entire length of the pin, a firm holding action will be obtained @and the blade will be seated along its entire length. Since, however, the pin is supported in its groove 16, the fit can be so made; that whilethe blade is firmly suppinsgreinain in position matching takes place in such a way that the lower erlges 17 andQO substantially coincide so that'the pin 14, upon being driven into the taper slot, will engage the blade 6 along an extended portion otthe pin, that is,

throughout practically its entire length and 5 along a line parallel with the seat of the blade 6.- The position of the edges-l7 and 20 such that their relation to each other is not altered by movement of the blade along the slot and up the inclined bottom 5. 'At the same time the pins 14: provide effective holding elements for holding the blades in their seats in whatever blades maybe.

adjusted position the -At the end of each taper groove, a drift receiving recess 21 provided 1n the head 1.

This recessprovides access to the tip of the 4.0

pin 14 so that the same may be dislodged by inserting a drift in the recess 21 so that the blade may be removed or replaced. 'ltwill' be evident, therefore, that this invention. provides a simple and eflect1vereaming tool and one which can be easily and positively-adjusted and retained in adjusted position. The adjusting ring 10 may be w'orked'along. the thread9 so as to move the blades along the slots and up the inclined bottom 5 in order to expand the blades.

lVhen proper adjustment has been obtained, v the backing ring 12 may be tightened so that the blades Will remain in, adjusted posit'on. The pins may easilybe loosened by inserting a drift in the recess 21, when the blades are to be removed.

made in details of construction Without departing from the spi'rt of. (this invention; it is, therefore, to be understood that this invention it not to be limited to the specific details shown and described.

i "It is obvious that. various changes may be Having thus described the inventiomwhat is claimed is: 7

-l.'AI1 expansion reamer, comprising, a head having inclined slots therealong, blades adjustable in said slots, taper grooves in said head and matching with corresponding straight grooves in and alongl'sjaid blades,

each "pair ofmatching grooves vintersecting along a line parallel With the bottom of its respective slot, and a taper pin in ;each

pair of matching grooves and bearing against the-walls thereof, adapted to seat said blades in'said head. v

2; An expansion -reamer, comprising, a head having inclined slots therealong, blades adjustable in said slots, straightgrooves in and along said blades, taper grooves in said 'head matching said straight grooves but inclined thereto and intersecting. along a line parallelto the respective seats, and a taper pin in each pair of matching grooves adapted to guide said blades for adjustment. 1 v

3. An expansion reamer comprising,

head havinginclined slots therealong, blades adjustable in said slots, the blade having a straight groove parallel to the bottom ofa'w:

the slot forsaid blade, the side of the. slot having a tapered groove with the portion intersecting the groove in the blade'coinciding therewith, and. a tapered pin'bearing Where it contact-swith the tapered groove along its full length. a a

- In testimonywhereof Iafiix my signature this 1st day of September, 1922;

" i EMERY nnAvIs, 

